3 Answers
3

(BTW, I am informed that there is now an NPI tag, which anyone is allowed to use to mark questions with. Feel free.)

Whenever you see a negative (like never) in a sentence, you know you've got trouble. Especially if you see more than one, or if there's a modal in the sentence as well. Luckily, that's not the case here.

First, NPIs. The word ever means at any time, i.e, *anywhen. Except people don't say *anywhen (the asterisk means it's ungrammatical); they say ever instead, the same way they don't say *all two, but rather say both instead.

The interesting thing about the word ever is that it's a Negative Polarity Item (NPI), like any; indeed, it's just a variant of any. NPIs can't occur outside a negative context, which is why it sounds so awful to say

*I have ever been there.

That's why there's a not in

I have not ever been there.

Never is just a contraction of not ever, the same way none is a contraction for not one.

I have never been there.

Both of those are fine, because they're negative. One is a contraction of the other, so there's no meaning difference.

As for such a thing, it's an idiom, in this case a pretty frozen one, which indicates surprise at the extreme nature of whatever the "thing" is sposta be. So you get to express surprised indignation at the same time you deny experience of extremes. Pretty useful phrase.

Good answer (I guess), but I didn't understand the conclusion. Do you mean both usages are same and valid?
–
yasarAug 10 '12 at 21:31

Yes. Just like He has done it and He's done it are same and valid. Contractions don't change meaning.
–
John LawlerAug 10 '12 at 21:57

1

I say 'anywhen', and so did Thomas Carlyle. ‘Ever’ outside a negative context hasn’t always been ungrammatical, and I’m not sure it is now. We still say, if a little self-consciously, ‘It was ever thus’.
–
Barrie EnglandAug 11 '12 at 7:33

Fixed phrases are exceptions to any rule. They preserve archaic structures, like fossils in the landscape; in the UK, where Englishes have been spoken the longest, they often preserve archaic local structures. However, they are fossils, and they're not really productive in Modern English.
–
John LawlerAug 11 '12 at 14:54

I think there's a subtle difference in meaning, at least in my dialect: "I didn't ever..." often has more force/emphasis than "I never.." One may say, "I never saw him do that". The emphasis is on "saw" and the implication could be that he may have done it for all I know, but I didn't see it. But if I say, "I didn't ever see him do that", then the emphasis is on "ever", which gives an implication is more along the lines of I don't think it ever happened.
As I said, it's not 100% consistent, but there often is that distinction. You have to rely on context for full clarity.

Both usaages are correct, and the meanings are identical. I don't agree with your third paragraph though; you may find that in some regions, one is more common than the other, but I would be very surprised if you find any region at all where the meaning differs.
–
user16269Aug 10 '12 at 22:40